Progress Toward a Total Synthesis of the Welwitindolinone Alkaloids PDF Download
Are you looking for read ebook online? Search for your book and save it on your Kindle device, PC, phones or tablets. Download Progress Toward a Total Synthesis of the Welwitindolinone Alkaloids PDF full book. Access full book title Progress Toward a Total Synthesis of the Welwitindolinone Alkaloids by Matthew Mark Weiss. Download full books in PDF and EPUB format.
Author: Matthew Mark Weiss
Publisher:
ISBN:
Category :
Languages : en
Pages : 1242
Get Book Here
Book Description
Author: Matthew Mark Weiss
Publisher:
ISBN:
Category :
Languages : en
Pages : 1242
Get Book Here
Book Description
Author: Jason Patrick Burke
Publisher:
ISBN:
Category :
Languages : en
Pages :
Get Book Here
Book Description
Author: Leah Brigit Cleary
Publisher:
ISBN: 9781303305948
Category :
Languages : en
Pages : 579
Get Book Here
Book Description
This thesis documents progress on five distinct projects pertaining to advancing methodologies and the synthetic utility of the Diels-Alder reaction. The first methodical study used a microwave reactor as convenient and safe heating source to induce the type 2 intramolecular Diels-Alder reaction. The second methodology involves the synthesis and study of bis-borane Lewis acids as chiral catalysts of intermolecular Diels-Alder reactions and ionic Diels-Alder reactions. A computational study to determine the origins in regio- and diastereoselectivity of the N-acylnitroso type 2 intramolecular Diels-Alder reaction accompanies our synthetic efforts toward the total synthesis of the Stemona alkaloid, ( - )-stenine. Finally, progress toward the total synthesis of the welwitindolinone alkaloids, N-methyl welwitindolinone C isothiocyanate and N-methyl welwitindolinone B isothiocyanate, is reported.
Author: Yasamin Moazami
Publisher:
ISBN:
Category :
Languages : en
Pages : 195
Get Book Here
Book Description
Author: Jianwen Cui
Publisher:
ISBN:
Category : Tetrahydroisoquinolines
Languages : en
Pages : 0
Get Book Here
Book Description
Author: Alberto Michael Lopez
Publisher:
ISBN:
Category : Chemistry, Organic
Languages : en
Pages : 308
Get Book Here
Book Description
The Daphniphyllum alkaloids are polycyclic natural products isolated from evergreen trees and shrubs native to areas of Southeast Asia. Their structural complexity and biological activity has motived the synthetic community to devise unique strategies to access these molecules. An elegant biomimetic synthesis of methyl homodaphniphyllate by Heathcock and co-workers in 1992 was the first reported total synthesis of a Daphniphyllum alkaloid. In the years since that report, approximately 300 Daphniphyllum alkaloids have been isolated and reported. This recent flood of discovery has been met with an analogous upsurge of interest. Since 2011, 10 total syntheses and several partial syntheses of Daphniphyllum alkaloids have been reported. In our retrosynthetic analysis of calyciphylline A and daphnicyclidin-type alkaloids, we imagined that a N-centered radical tandem cyclization would rapidly build their tricyclic. Indeed, this key cyclization was achieved and we were compelled to pursue the total synthesis of the target molecules.
Author: Xiangna Jia
Publisher:
ISBN:
Category : Alkaloids
Languages : en
Pages : 366
Get Book Here
Book Description
Author:
Publisher:
ISBN:
Category : Dissertation abstracts
Languages : en
Pages : 776
Get Book Here
Book Description
Author: Ningzhang Zhou
Publisher:
ISBN:
Category : Tetrahydroisoquinolines
Languages : en
Pages : 0
Get Book Here
Book Description
Author: Jennifer Pitzen
Publisher:
ISBN: 9781339528717
Category :
Languages : en
Pages : 207
Get Book Here
Book Description
Progress towards the total synthesis of N-methylwelwitindolinone C isothiocyanate is reported. The tetracyclic core is established by a key alkylation--type 2 intramolecular Diels--Alder cascade reaction, forming three new carbon-carbon bonds and five stereocenters in one step. Mechanistic studies suggest that alkylation proceeds via a zinc enolate intermediate instead of a silyl ketene aminal, shortening the synthesis by one step. Elaboration of the welwitindolinone core was accomplished with novel use of chlorinating agent MoCl5 to selectively convert a ketone to the vinyl chloride found in the natural product. To circumvent the problematic differentiation of two esters and install a bridgehead amine at an early stage in the synthesis, a series of new dienophiles were prepared. Ultimately selective protection of a diol intermediate allowed for differentiation, but methylation to install the final quaternary center proved to be challenging and remains one of the last hurdles in completing the synthesis.
